The study found that while the most common symptoms include loss of smell, shortness of breath and chest pain, others include amnesia, erectile dysfunction, hallucinations, an inability to perform familiar movements or commands, bowel incontinence and limb swelling.
Patterns of symptoms tended to be grouped into respiratory symptoms, mental health and cognitive problems, and then a broader range of symptoms.
As well as spotting a wider set of symptoms, researchers also identified key groups and behavior that put people at increased risk of developing long Covid.
As reported last montha record 2 million people in the UK are estimated to be suffering from long Covid, according to the Office for National Statistics (ONS).
Around 3.1 per cent of the British population are suffering symptoms that persist for more than four weeks after catching Covid. Some 376,000 people who first caught Covid around the start of the pandemic have reported symptoms lasting at least two years.
The study suggests that females, younger people, and those belonging to a Black, mixed-race or other ethnic group are at greater risk of developing long Covid.
Additionally, those from a poorer background, smokers, and people who are overweight or obese, as well as those with any of a wide range of health conditions, were more likely to report persistent symptoms.
Senior author Dr Shamil Haroon is an associate clinical professor in public health at the University of Birmingham.
He said: “This research validates what patients have been telling clinicians and policymakers throughout the pandemic – that the symptoms of long Covid are extremely broad and cannot be fully accounted for by other factors, such as lifestyle risk factors or chronic health conditions.
“The symptoms we identified should help clinicians and clinical guideline developers to improve the assessment of patients with long-term effects from Covid-19, and to subsequently consider how this symptom burden can be best managed.”
People who tested positive for the virus reported 62 symptoms much more frequently 12 weeks after initial infection than those who had not contracted the virus, the study found.
The NHS list of common Covid symptoms includes fatigue, shortness of breath, chest pain or tightness, and “brain fog”.
Researchers from the University of Birmingham analyzed the anonymised electronic health records of 2.4 million people in the UK alongside a team of clinicians and researchers across England.
The data obtained between January 2020 and April 2021 comprised the records of 486,149 people with prior infection, and 1.9 million people with no indication of coronavirus infection after matching for other clinical diagnoses.
Using data from patients who had not been admitted to hospital, the team of researchers was able to identify the three distinct categories of symptoms.
Anuradhaa Subramanian, research fellow at the Institute of Applied Health Research at the University of Birmingham and lead author on the paper, said: “Our data analyzes of risk factors are of particular interest because it helps us to consider what could potentially be causing or contributing to long Covid.”
She added: “Women are, for example, more likely to experience autoimmune diseases. Seeing the increased likelihood of women having long Covid in our study increases our interest in investigating whether autoimmunity or other causes may explain the increased risk in women.
“These observations will help to further narrow the focus on factors to investigate what may be causing these persistent symptoms after an infection, and how we can help patients who are experiencing them.”
The findings are published in NatureMedicine.